Numbering Resources

5XX-NXX Assignments

5XX-NXX codes are to be used for applications which are non-geographic in nature, are not assigned to rate centers and may or may not traverse the PSTN, but do require an E.164 addressing scheme. The use of this NANP numbering resource is to communicate with both fixed and mobile devices, some of which may be unattended. This resource may be used for applications enabling machines, which would include but not be limited to wireless devices and appliances, the ability to share information with back-office control and database systems and with the people that use them. Service is limited only by terminal and network capabilities and restrictions imposed by the service provider.

5XX-NXX codes are in the format 5XX-NXX-XXXX. 5XX-NXX codes, each subsuming a block of 10,000 numbers, are assigned to service providers.

5XX-NXX codes are assigned according to guidelines developed by the Industry Numbering Committee, which is sponsored by ATIS.

Service provider applicants for an initial code assignment shall provide, as part of their application, evidence that demonstrates the service provider has a license or authorization issued by the appropriate regulatory authority [e.g. the FCC or a Certificate of Public Convenience and Necessity (CPCN) issued by a State Regulatory Body to provide service in the city and state/rate center/MSA#/RSA# /MTA#/BTA#/national /LATA].

Historical Summary: The North American Numbering Plan Administrator (NANPA) initially assigned the 500 NPA code for use with personal communications service, and the INC subsequently designated the 533, 544, 566, 577, 588 and 522 NPA codes for future personal communications service and other non-geographic services. With the designation of these NPA codes, the resource was referred to as the "5YY" resource. In 2012, INC agreed (Issues 692/702) the current service description for 5YY resources limited their use to a more narrow application than what was needed in today's marketplace. INC decided to revise and expand the service description for 5YY resources to include emerging technologies such as machine-to-machine or other non-geographic applications to ensure efficient use of NANP resources. Further, in May 2012 (Issue 703), the following NPAs were set aside to augment the 5YY resources: 521, 523, 524, 525, 526, 527, 528, 529, 532, 538, 542, 543, 545, 547, 549, 552, 553, 554, 556, 569, 578 and 589. In September 2013 (Issue 758), additional NPAs were set aside for future Non-Geographic 5XX-NXX Code Use: 550, 535, 546, and 558. These were in addition to the previously-reserved NPAs 577, 588, and 522. Finally, since these NPAs were no longer in the form of Easily Recognizable Codes (ERCs), INC agreed to retitle the "Personal Communication Services (PCS) 5YY NXX Code Assignment Guidelines" as the "Non-Geographic 5XX-NXX Code Assignment Guidelines" and refer to the resource as "5XX-NXX" codes.